Voxel-based morphometry (VBM) analysis in Alzheimer's disease an insight into heterogeneity of cerebral atrophy

Depletion of estrogens and progesterone at menopause has been linked to an increased risk for the development of Alzheimer’s disease (AD) in women. A currently controversial literature indicates that although treatment of postmenopausal women with hormone therapy (HT) may reduce the risk of AD, several parameters of HT may limit its potential efficacy and perhaps, even exacerbate AD risk. One such parameter is continuous vs. cyclic delivery of the progestogen component of HT. Recent experimental evidence suggests that continuous progesterone can attenuate neural actions of estradiol (E2). In the present study, we compared the effects of continuous and cyclic progesterone treatment in the presence and absence of E2 in ovariectomized 3×Tg-AD mice, a transgenic mouse model of AD. We found that ovariectomy-induced hormone depletion increases AD-like pathology in female 3×Tg-AD mice, including accumulation of β-amyloid, tau hyperphosphorylation, and impaired hippocampal-dependent behavior. E2 treatment alone prevents the increases in pathology. Continuous progesterone did not affect β-amyloid levels when delivered alone but blocked the Aβ-lowering action of E2. In contrast, cyclic progesterone significantly reduced β-amyloid levels by itself and enhanced rather than inhibited the E2 effects. These results provide new insight into the neural interactions between E2 and progesterone that may prove valuable in optimizing HT regimens in postmenopausal women.

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Induced Pluripotent Stem Cell-Derived Neural Precursors Improve Memory, Synaptic and Pathological Abnormalities in a Mouse Model of Alzheimer’s Disease

Cells ◽

10.3390/cells10071802 ◽

2021 ◽

Vol 10 (7) ◽

pp. 1802

Author(s):

Enrique Armijo ◽

George Edwards ◽

Andrea Flores ◽

Jorge Vera ◽

Mohammad Shahnawaz ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Clinical Symptoms ◽

Memory Loss ◽

Amyloid Β ◽

Cerebral Atrophy ◽

Brain Inflammation ◽

Neural Precursors ◽

Model Of Alzheimer’S Disease ◽

Induced Pluripotent

Alzheimer’s disease (AD) is the most common type of dementia in the elderly population. The disease is characterized by progressive memory loss, cerebral atrophy, extensive neuronal loss, synaptic alterations, brain inflammation, extracellular accumulation of amyloid-β (Aβ) plaques, and intracellular accumulation of hyper-phosphorylated tau (p-tau) protein. Many recent clinical trials have failed to show therapeutic benefit, likely because at the time in which patients exhibit clinical symptoms the brain is irreversibly damaged. In recent years, induced pluripotent stem cells (iPSCs) have been suggested as a promising cell therapy to recover brain functionality in neurodegenerative diseases such as AD. To evaluate the potential benefits of iPSCs on AD progression, we stereotaxically injected mouse iPSC-derived neural precursors (iPSC-NPCs) into the hippocampus of aged triple transgenic (3xTg-AD) mice harboring extensive pathological abnormalities typical of AD. Interestingly, iPSC-NPCs transplanted mice showed improved memory, synaptic plasticity, and reduced AD brain pathology, including a reduction of amyloid and tangles deposits. Our findings suggest that iPSC-NPCs might be a useful therapy that could produce benefit at the advanced clinical and pathological stages of AD.

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Reproducibility of Brain Volume Changes in Longitudinal Voxel-Based Morphometry Between Non-Accelerated and Accelerated Magnetic Resonance Imaging

Journal of Alzheimer s Disease ◽

10.3233/jad-210596 ◽

2021 ◽

pp. 1-10

Author(s):

Hidemasa Takao ◽

Shiori Amemiya ◽

Osamu Abe ◽

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Magnetic Resonance ◽

Gray Matter ◽

Gray Matter Volume ◽

Elderly Subjects ◽

Voxel Based Morphometry ◽

Volume Changes ◽

Matter Volume ◽

Healthy Elderly

Background: Scan acceleration techniques, such as parallel imaging, can reduce scan times, but reliability is essential to implement these techniques in neuroimaging. Objective: To evaluate the reproducibility of the longitudinal changes in brain morphology determined by longitudinal voxel-based morphometry (VBM) between non-accelerated and accelerated magnetic resonance images (MRI) in normal aging, mild cognitive impairment (MCI), and Alzheimer’s disease (AD). Methods: Using data from the Alzheimer’s Disease Neuroimaging Initiative (ADNI) 2 database, comprising subjects who underwent non-accelerated and accelerated structural T1-weighted MRI at screening and at a 2-year follow-up on 3.0 T Philips scanners, we examined the reproducibility of longitudinal gray matter volume changes determined by longitudinal VBM processing between non-accelerated and accelerated imaging in 50 healthy elderly subjects, 54 MCI patients, and eight AD patients. Results: The intraclass correlation coefficient (ICC) maps differed among the three groups. The mean ICC was 0.72 overall (healthy elderly, 0.63; MCI, 0.75; AD, 0.63), and the ICC was good to excellent (0.6–1.0) for 81.4%of voxels (healthy elderly, 64.8%; MCI, 85.0%; AD, 65.0%). The differences in image quality (head motion) were not significant (Kruskal–Wallis test, p = 0.18) and the within-subject standard deviations of longitudinal gray matter volume changes were similar among the groups. Conclusion: The results indicate that the reproducibility of longitudinal gray matter volume changes determined by VBM between non-accelerated and accelerated MRI is good to excellent for many regions but may vary between diseases and regions.

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Neuropathological Alzheimer’s Disease Lesions in Nasu-Hakola Disease with TREM2 Mutation: Atypical Distribution of Neurofibrillary Changes

Journal of Alzheimer s Disease ◽

10.3233/jad-201085 ◽

2021 ◽

Vol 79 (1) ◽

pp. 25-30

Author(s):

Emanuela Maderna ◽

Silvia Visonà ◽

Vittorio Bolcato ◽

Veronica Redaelli ◽

Paola Caroppo ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Autosomal Recessive ◽

Cerebral Atrophy ◽

Autosomal Recessive Disorder ◽

Homozygous Mutation ◽

Neurofibrillary Changes ◽

Axonal Spheroids ◽

Temporal Structures ◽

Cortical Involvement

Nasu-Hakola disease is a rare autosomal recessive disorder associated to mutations in TREM2 and DAP12 genes, neuropathologically characterized by leukoencephalopathy with axonal spheroids. We report the neuropathologic findings of a 51-year-old female with a homozygous mutation (Q33X) of TREM2 gene. Beside severe cerebral atrophy and hallmarks of Nasu-Hakola disease, significant Alzheimer’s disease lesions were present. Neurofibrillary changes showed an atypical topographic distribution being severe at spots in the neocortex while sparing the mesial temporal structures. Our finding suggests that TREM2 genetic defects may favor Alzheimer’s disease pathology with neurofibrillary changes not following the hierarchical staging of cortical involvement identified by Braak.

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